Tissue velocity imaging during dobutamine stimulation for assessment of myocardial viability: Segmental analysis in patients after myocardial infarction

Abstract

Background Dobutamine stress echocardiography (DSE) is an established method for the detection of viable myocardium, but evaluation of this method is subjective. Tissue velocity Imaging (TVI) allows quantitative analysis of regional myocardial wall motion by assessment of systolic myocardial velocities. The aim of this study was to evaluate the diagnostic value of DSE and TVI for detection of viable myocardium. Methods In 56 patients (58 ± 12 years) with previous myocardial infarction (130 ± 42 days, mean ejection fraction 42 ± 15%) low-dose DSE was combined with analysis of peak systolic myocardial velocities ( V peak) by TVI for assessment of myocardial viability. As reference served a follow-up echocardiography after successful revascularization (mean 91 ± 3 days). Results Of a total of 896 segments 200 showed abnormal wall motion (31 mildly hypokinetic, 50 severely hypokinetic, 115 akinetic, 4 dyskinetic). In 125 of these 200 segments regional improvement of regional wall motion was observed (62.5% viable). An increase of V peak > 1 cm/s during dobutamine stimulation allowed the identification of viable myocardium with a sensitivity of 82% and a specificity 82% (DSE: 77% and 80%). By receiver operating characteristic (ROC) curve analysis, a cut-off value of 1.0 cm/s was the best parameter to differ viable from nonviable myocardium (area under the curve 0.85; p < 0.01; 95% CI 0.79 to 0.90). Improvement of global ejection fraction after revascularization (47 ± 13%, p = 0.11) corresponded with three TVI viable segments with a sensitivity of 92% and a specificity of 89% ( p = 0.012). Conclusions TVI allows the identification of viable myocardium during dobutamine stimulation and enables a quantitative interpretation of DSE.